ABSTRACT
There are over 300 timber bridges on Queensland state controlled roads which require constant maintenance as the timber components deteriorate over time. Inspections are done at three levels depending on the necessity. A significant number of the defects are due to poor practices such as excessive sniping of girders and corbels, which contribute to many bridges being rated in poor condition. This causes costs to increase due to increased inspection frequencies and rectification works. The aim of this research is to critically investigate the effect of sniping on the overall structural performance of individual bridge elements. Based on inspection reports for timber bridges, it is understood that sniping is a major issue and it contributes towards the deterioration of the whole member. Structural analysis has been carried out using finite element modelling in Ansys. Finite element modelling allows idealised timber components to be analysed under different loading conditions. This has been used to compare the effect of snipe depth on the structural integrity of timber components such as girders and corbels. As snipe depth increases, stress concentrations form at the snipe resulting in increased risk of splitting. Based on this modelling, some recommendations are made regarding the future assessment of component condition states.
